With the rapid development of information industry, the development of modern high-frequency communications has put forward higher and higher requirements for the electrical properties of materials, the copper-clad laminates used on the high frequency circuits must have good dielectric properties, which requiring the substrate materials to have a lower dielectric constant and a smaller dielectric dissipation factor. Generally, the signal propagation velocity within the conducting wire in the circuit board satisfies the equation V=K*C/ε2, wherein C is the velocity of light, ε is the dielectric constant, and K is a constant. It can be seen that if ε is smaller, the propagation velocity is faster. In addition, the transmission loss in the signal propagation is related to the loss within the conductor and the loss within the medium. The loss within the conductor is in direct proportion to the square root of ε, and the loss within the medium is related to the square root of ε and the loss tangent. Therefore, the use of substrate materials having low dielectric constant and low dielectric dissipation factor facilitates the high speed transmission of signals and the reduction in the loss of signals.
However, at present, the dielectric constant (Dk) of the ordinary FR-4 under the condition of 1 GHz is between 4.3 and 4.8, and its dielectric dissipation factor (Df) is between 0.02 and 0.025, which cannot satisfy the transmission speed of high frequency signals and the integrity of signal transmission.
Since the outer side of the main chain of the silicone resin macromolecule has a layer of non-polar organic groups and the macromolecular chain has molecular symmetry, it has excellent electrical insulation properties, its dielectric constant and dielectric loss tangent value vary very little within a wide temperature range and frequency range, which meanwhile can remain constant at 200° C. or less and can act as an ultrahigh frequency insulation material used at 350° C. In a variety of curing ways of silicone resin, the reaction between —CH═CH2 and —Si—H catalyzed by platinum is under mild conditions, no small molecule will be released when curing, and no bubble will be generated, thus it has very superior electrical properties.